Production of alkali metals.



almost no metal is separated If perature of the electrolyte is kept low'enough}, however, it. is possible to obtam excellent re -f This: fact hasfli use UNITED STATES H GEORGE o. SEWARD ANDFRANZ voN Kn EL'GEN. onnoneo Bs-nooK,

:AHRGINIA. j

Be it known that we, GEORGE O.

ginia, have jointly inventedcertain 'fnwfand l Improvements injth e specification, In the production electrolysisofthe a1;

kah metals from their chlorids itgis -neces-fl sary to employ an electrolyte of low-melting.

point, for the reason that the outputiof metal eIectr-o-f, eratu the tem'-' decreases as the temperat f t lyte mcreases, until" at ;e ga sp -m sultsand high efficiencies.

. been generally recognized by .thosjeskilled the art, and various electrolyteshave been Proposed.-.-

For the production N aCl' and N aF has been proposed,also a mixture of NaCl-and K01; but these have the disadvantage of not melting: atiasql'ow atemperature as is desirable to give the best results. Other electrolytes proposed are a mixture of N aCl, K01, and' an earth-alkali chlorid; also, a mixture of NaCl,'KCl', and

N aF, the two latter reacting to form'KF, so

that the mixture is essentially one of N aCl and KF.- Both of these electrolytes have very low melting-points; but the presence of a potassium salt is undesirable, as there is a tendency of a part of the potassium salt to be decomposed-with the sodium salt, so that the sodium produced is contaminated with potassium. f a I The'present invention provides an electrolyte which does not possess any of the disadvantages of electrolytes previously used in the manufacture of alkali metals and which possesses the desirable features of the best of them.

It consists in the combination of the chlorid of the alkali metal sought, a fluorid of the same metal, and a chlorid of an earthalkali metal.

I As an example of our invention for the production of sodium we use a mixture of N aOl, N aF, and BaOl This electroly to reduction of potassium We use a mixture of 1 Specification of Letters P e.

For he pro- K01, Kr, a

these, electrolytes the th e i 0 a fisrfi "ali metal song] t by; another alkali ,'.metal',-

. atthef current density'iis'd in theprodufction o'fthealkalimetal;

earth-alkali salts, if deslred.

fpartslN'aF, one "part BaCl and subject the amount of sodium'fluorid is also fed in to constant.

'tioned proportions of ingredients of-a sodium electrolyte may be considerably varied without departure from the invention and with out particular disadvantage, although the -.ent experience indicates as giving the best re- 'sults.

Similar We claim as our invention- 1. .The production of an alkali metal b1: the electrolysis of the chloridpf the alkali metal. sought, with the addition of fluorid of the same metal and metal.

trolysis of a fused mixture of sodium chlorid, sodium fluorid, and a chlorid of an earth-alkali metal, substantially as described. I

In, Witness whereof we have hereunto signedpur names in the scribing witnesses. a

GEORGE O. SEWARD'. FRANZ VON KUGELGIIEN- P.':,O. HARDING.

, 1 Patented ing'le'earth alkali salt-with the alkali salts jitf j. being of no disadvanta em use two or more a F r the production of metallic :use'as an electrolyte four parts NaCl, twlokeep the proportion of that salt substantially proportions stated are those which our presj-J proportions of the corresponding"- salts are suitable fora potassium electrolyte. Y

2. The production of sodium by the'eleca ea lialkaline clilorid,such; jas Ba'Clw-l Besides the low melting-points of eat advantage is that t contaminating the al-f 6p 511iC' l;l 16Barthalk&li salt is not decomposed":

fusedmixtureto electrolysis in a suitable ap-" "-paratus, where the separated metal is kept a a t fromthehaloge'n and protected from it e action of the air. Only sodiumvchlorid, with a"very-small proportion of sodium; fluorid, is decomposed. From time'to' time; sodium chlorid is fed in to replace thatde composed, and at longer intervals a small of sodium a mixture of- It will be understood that the above-meni7 chlorid of an earth alkali presence of two sub- 

